A grow light is an artificial light source designed to stimulate plant growth by emitting an electromagnetic spectrum appropriate for photosynthesis. Grow lights are used in applications where there is either no naturally occurring light, or where supplemental light is required. Examples are for growing plants during the winter months when the available hours of daylight may be insufficient for the desired plant growth and/or used to extend the amount of time the plants receive light.
Grow lights either mimic the light spectrum of the sun or provide a light spectrum that is designed for plants being cultivated. Outdoor conditions are mimicked with varying color temperatures and spectral outputs from the grow light, as well as varying the lumen output of the lamps. Further, the photoperiod required by the plants, specific ranges of spectrum, luminous efficacy and color temperature can be varied as desirable for use with specific plants and time periods.
Grow lights systems have been known and used for many years for a wide range of growing systems and for a wide range of plants. In recent years, grow light systems have been used with hydroponic growing systems to both improve the growth of the plants and to allow these systems to be used year round. However, while it has been found that grow lights can improve the growth of plants, grow lights have penetration limits. In this respect, as plants grow taller and become more dense, grow lights of the prior art start failing to fully penetrate the plant and, therefore, have functional limits on the size of plant that they can fully support. While, the prior art systems will still promote growth of these larger plants, it has been found that their restricted light penetration prevents maximum growth of the plant. Therefore, increasing the light penetration can reduce this growth restriction and allow grow light systems to be used on larger plants and grow larger plants.